EP2146868B1 - Active head support for rear bench seats in a passenger vehicle - Google Patents

Abstract

The present invention relates to a head support for installation in vehicle seats, movable from a normal position to an accident position by means of a sensor-activated mechanism. In order to be able to reuse the head support and to provide for reduced crash impact on the persons in case of an accident, a head support is proposed wherein a) a housing body (14) of the head support can be rigidly connected to the seat, b) an upper impact plate (16) and a lower impact plate (18) are connected to the housing body by the mechanism, c) wherein the upper impact plate (16) is pivotally supported in an erected, substantially vertical position from a substantially horizontal position, d) wherein the mechanism is equipped to move the lower impact plate (18) forward to engage the accident position, e) and simultaneously to tilt the upper impact plate (16) upward about a connecting axis between the upper and lower impact plates.

Description

State of the art

The present invention relates to a headrest for installation in seats of vehicles, which can be moved from a normal position to an accident position, by means of a mechanism which can be activated by a sensor. Such a seat according to the preamble of claim 1 is for example from the DE 103 00 978 A1 known.

Today, the headrests in many automobiles are part of the passive safety system. Some headrests, known as active head restraints, lean forward when impacted so they can catch the head a few milliseconds earlier.

In the passenger occupant protection sector, while there is currently the option of choosing between different driver or passenger protection systems, passengers in the backseat are disadvantageously unavailable on the market, although in principle all occupants are equally vulnerable during an accident endangered and in need of protection.

In frontal impact, for example, the occupant is accelerated by the rearward braking in the direction of travel and ideally absorbed by the belt, which already absorbs part of the energy. The body is then thrown back against the seat and headrest, which must absorb the rest of the energy of the impact.

From a medical point of view, these jerky movements cause very heavy loads in the area of the cervical vertebrae. This phenomenon, also referred to as cervical spine syndrome (cervical spine), results from the fact that the upper body and the head can be accelerated to different degrees by the impact from behind.

The consequences are overstretched ligaments in the head and neck area, nerve bruising, inflammation, bleeding, displacement or even fractures of vertebrae.

The treachery of cervical spine distorsions is that the risk of injury does not necessarily depend on the impact force, as even minor crashes can cause injury. Sometimes complaints only appear after days. Symptoms include head and neck pain, nausea, sleep and concentration problems, blurred vision and dizziness, as well as paralysis.

The cervical spine whiplash (cervical spine twisting, cervical spine syndrome), which is also known as whiplash injury (whiplash phenomenon), is one of the most prevalent in front-or rear-end collisions, representing the most common accident constellations the insurance industry most expensive injuries, accounting for about 75% of all costs.

Particularly bad injuries are possible if the head restraints are set too low. This will cause the head to bounce over the headrest. Another cause of injury may be too great a distance the head will take to the headrest, for example, through a relatively loose and relaxed seating position. This leads already from a distance of more than three centimeters to an increase in the risk of injury, as a result of the greater distance the head hits with a higher energy.

In the prior art, for the purpose of triggering the mechanism of an active headrest usually a pressure sensor is used as a so-called impact target, which is mounted in the seat interior. However, this approach has disadvantages, since this always a compromise comfort of the seat back and release safety must be found, because the security for triggering the mechanism is only given if between the baffle and the back-fasting back of the seat occupant is not too thick pad. This causes impairments of comfort.

Another problem with the pressure sensors as part of the release mechanism is the actual trigger safety, which is only given when the body hits the impact target with a certain weight and a speed associated with it. So it can happen that small, petite people due to their low body weight or small size, the mechanism does not trigger. It can also happen that the body of the seat occupant of whatever kind circumstances in the crash is not in the normal seating position and thus does not meet the impact target of the release mechanism optimal. Even if the impulse from a crash does not come from behind, but rather from the rear, the body of a seat occupant may miss the impact target. The disadvantages of systems with such pressure receiving devices within the backrest are thus diverse, since the optimal safety is guaranteed by the system only by absolute ideal or standard conditions.

In the prior art and electronically triggered systems are known. These can disadvantageously reduce the distance between the head and the headrest only to a relatively limited extent, or are uneconomical because, for example, they are not reusable after an impact similar to an airbag.

It is an object of the present invention to develop an active headrest so that it is reusable and provides in an accident for a reduced crash load for the people.

Advantages of the invention

With the measures of the independent claim, the problem is solved.

In the dependent claims advantageous refinements developments and improvements of the respective subject of the invention are given.

This object is essentially achieved in that the headrest consists essentially of three parts, a housing body, a lower baffle plate and an upper baffle plate, and anchoring means for the housing body in the seat, preferably at the upper edge of the seat back, wherein the upper baffle plate and which is connected under baffle to the housing body by a mechanism, wherein the mechanism is adapted to move to take the accident position, the lower baffle plate forward and at the same time to pivot the upper baffle plate up around a connecting axis between the upper and lower baffle plate the upper baffle plate is pivotable from a substantially horizontal orientation to an upright, substantially vertical orientation.

The pivoting movement is preferably effected by a leg spring, the leg rests on the one hand on an articulated arm and on the other hand on the inside of the upper baffle plate. Other, equally acting forces, for example prestressed air spring elements, can also be used for this purpose become. If the end position of this pivoting movement is reached, a detent prevents swiveling back. The forward movement is a linear movement which is guided by respective guides and is effected by a force, preferably from a spring, which pushes or pulls in the direction of the linear movement.

The triggering of the mechanism is preferably carried out by coupling with an airbag activation signal, which controls a magnetic switch or a similar switching device, with which the two aforementioned and prestressed spring elements are released, for example by pulling a locking pin. After triggering in an accident, the headrest according to the invention can be manually moved back to the normal position, the spring elements are biased again and locked there.

The headrest according to the invention is particularly suitable for car rear seat benches or individual seats in the rear area, because the headrest is easily removable and repluggable, and then immediately fully functional.

In a preferred embodiment, mechanical springs are provided to perform the forward linear movement and the pivotal movement to manually return the headrest to its normal position upon release of the system.

Advantageously, a cost-effective integration of the headrest according to the invention in new or existing seating systems is easily possible because no structural changes to a seat are required, because the coupling between inventive headrest and seat back can be done on the often used in the prior art two vertical struts, the dive deep into the interior of the back and are held there rested.

In the case of the very advantageous coupling of the headrest according to the invention to a rear seat also the flexibility of the rear seat is maintained because the headrests are removable and the electrical connection to the actuators, such as a magnetic switch, can be separated by plug. This allows a rear seat to fold down easily and it retains its full, standard stability against payloads that may be in the trunk.

The active head restraints according to the invention offer a significantly increased safety compared to the prior art in that the head support surface in the event of an accident has a substantially further extension upwards, because the upper baffle plate rears upwards. This effectively prevents the person's head from banging over the headrest.

Secondly, the forward linear movement reduces the distance between the headrest and head, which reduces the impact velocity of the head on the lower and upper baffles.

Third, the headrest is significantly increased in the accident position, thereby reducing the pressure loads on the head. Furthermore, the active headrest according to the invention can be triggered electronically, whereby a reliable release in contrast to known in the prior art systems, this coupling can be made inexpensively, because it can be easily resorted to an existing airbag trigger signal.

The triggering is preferably done by a magnetic switch that moves a bolt, the upper and the holding the lower baffle plate in its normal position by locking in this position.

Finally, the headrest according to the invention can be made relatively low in its normal position, so as to affect the driver's view to the rear or to the side as little as possible. For this purpose, it is proposed to dimension the upper baffle plate relatively large and the lower baffle plate relatively small in height.

According to a further aspect of the present invention, the division into lower and upper baffle plate is further exploited to make the headrest in the normal position relatively small and relatively large in accident position: It is proposed that the upper baffle plate not in one piece, but telescoping in two smaller To perform pieces, wherein preferably only a slightly inhibited sliding fit between the two parts by two stable, connecting the two parts holding rails is provided. Due to the centrifugal force, which is effective anyway in the swivel movement carried out quickly, the telescopic movement can take place, with the upper baffle extends and increases significantly in size. In the contracted state of the normal position, the upper, in the embodiment horizontally oriented, upper baffle plate then has a much smaller size, which further improves the view to the side. The end position also has a detent again, so that the extended position remains stable for the entire accident situation.

This principle can also be applied multiple times, for example three parts, two telescope systems, or four / three ways, in order to extend the upper baffle plate even further upwards. Thus, increased protection against catapulted forward luggage from the hold of a station wagon can be achieved.

The headrest can be used in principle for front seats and rear seats or for individual seats and can be used as often as required, if the release mechanism is reversible. In a particularly preferred manner, the advantages of the electronically triggering systems are combined with those of the mechanically operating systems.

drawings

With reference to the drawings, embodiments of the invention will be explained.

• Figur 1 eine Ansicht der erfindungsgemäßen, aktiven Kopfstütze mit einstückig ausgeführter oberer Prallplatte in der Normalstellung, Fahrtrichtung nach links, mit Gehäusekörper, unterer Prallplatte, oberer Prallplatte und zwei vertikalen Streben zur Befestigung in einer Sitzlehne;
• Figur 2 die erfindungsgemäße Kopfstütze aus Figur 1 nach Auslösung des Mechanismus in halbgeöffneter Stellung, wobei die lineare Endstellung zur Verfahrung nach vorne bereits erreicht ist und die obere Prallplatte bereits in einem Winkel von etwa 45° nach oben aufgerichtet ist;
• Figur 3 die erfindungsgemäße Kopfstütze gemäß Ausführungsbeispiel und Fig. 1 und 2, wobei die obere Endstellung der Schwenkbewegung und damit die endgültige Unfallstellung erreicht ist.

Show it:

• FIG. 1 a view of the invention, active headrest with integrally executed upper baffle plate in the normal position, direction of travel to the left, with housing body, lower baffle plate, upper baffle plate and two vertical struts for attachment in a seat back;
• FIG. 2 the headrest according to the invention FIG. 1 after release of the mechanism in a half-open position, wherein the linear end position for reaching forward is already reached and the upper baffle plate is already erected at an angle of about 45 ° upwards;
• FIG. 3 the headrest according to the invention according to embodiment and Fig. 1 and 2 , wherein the upper end position of the pivoting movement and thus the final accident position is reached.

Description of exemplary embodiments

In the figures, the same reference numerals designate the same or functionally identical components.

FIG. 1 shows a view of the invention, the active headrest with upper baffle plate 16 in the normal position, direction of travel to the left, with housing body 14, lower baffle plate 18, upper, integrally executed baffle plate 16 and two vertical struts 12 for attachment in a seat back.

The vertical struts 12 are, as known in the art, provided with detents and can be retracted into a seat back and anchored there. The housing body 14 is fixedly connected to the vertical struts 12 and is adapted by a slightly curved base to the shape of the backrest edge. The upper baffle plate 16 is pivotally connected to the lower baffle plate 18 at a pivot axis 20. In the normal position, the upper baffle plate 16 is in a substantially horizontal, pivoted backward position and rests with its inside on the housing body 14. The lower baffle plate 18 rests with its inner side on the front side of the housing body 14. Preferably, the two baffles 16, 18 and the housing body 14 are made of plastic by injection molding and provided with a shock-absorbing intermediate layer and with a textile cover.

FIG. 2 shows the headrest according to the invention FIG. 1 after release of the mechanism in the half-open position, wherein the linear end position is already reached for moving forward and the upper baffle plate 16 is already erected at an angle of about 45 ° upwards;

FIG. 3 shows the headrest, the upper end position of the pivoting movement and thus the final accident position is reached.

With further relation to FIG. 2 and 3 the lower baffle plate 18 is connected to the housing body 14 by sliding guides 22. Such a sliding guide 22 is provided in the direction of travel right and left relatively far out to ensure an exact, linear displacement. The sliding guide 22 is formed in the example as a hollow cylinder which is fixedly connected to the lower baffle plate and in corresponding, not shown bores and can extend, which are provided on the housing body 14.

Another guide is provided in the middle of the two sliding guides 22 in the form of a likewise designed as a hollow cylinder cylinder guide 28. The cylinder guide 28 includes a hollow cylinder which is fixed to the lower baffle plate 18 and immersed in a provided in the housing body 14 corresponding hole. Inside the hollow cylinder 28 is a resilient element, here preferably an axial spring, which in the normal position FIG. 1 is compressed and striving to expand to those in FIG. 2 and 3 reach the position shown. The bias of the inner axial spring or a corresponding other force element should be chosen so that no own risk of injury to the person is generated by the rash of the lower baffle. There are stops provided to prevent the sliding guide 22 and the cylinder guide 28 can not solve their holes in the housing body 14 when the accident position is reached.

A locking edge 34 is fixedly secured to the rear or upper edge of the upper baffle plate 16, which engages a pin of a magnetic switch when the switch is in the normal position position. If the bolt is retracted by an electrical control pulse and the magnetic switch, so the lock 34 free and the axial spring inside the cylinder guide 28 can relax and drives the lower baffle plate forward.

At the same time pivots then the upper baffle plate 16 from its horizontal position in FIG. 1 in their vertical position in FIG. 3 , taking the intermediate position in FIG. 2 is shown.

The upper baffle plate 16 is adapted in shape to the contact surface to the lower baffle plate 18 by a corresponding rounded shape is formed as a contact surface on both baffles. The upper baffle plate 16 is connected to the lower baffle plate 18 by the pivot axis 20 and can be pivoted with respect to the latter by an angle of about 90 °, wherein stops are provided for both end positions.

How special FIG. 3 As can be clearly seen, the inside of the upper baffle plate 16 is connected to the housing body 14 by an articulated arm construction 24. In this case, the plate-side arm is firmly connected to the upper baffle plate and the housing-side arm runs with a pin in a guide groove 30 and snaps into the in FIG. 3 shown end position in a detent recess 32 of the guide groove 30, so that the pivoting movement after triggering can not be done without a manual lifting of the housing-side articulated arms. This is the stable position as in FIG. 3 shown ensured in case of accident. This Gelenkarmkonstruktion is preferably provided twice, once right and once left of the central cylinder guide 28 in order to achieve a high stability of the pivoting movement.

On both Gelenkarmkonstruktionen torsion springs 26 are provided, which in the in FIG. 1 shown normal position are biased and the upper baffle plate after release of the lock 34 in the in FIG. 3 shown accident situation so quickly that the whip effect shown above in the introduction can not occur with the head over the headrest under any circumstances.

The magnetic switch with a movable locking pin for triggering the lock 34 is not shown for the purpose of better clarity of the drawings; However, he sits in a preferred manner at the rear edge of the housing body 14, centrally between the two vertical struts. The electrical control by the airbag signal can preferably be done by electrical lines through the interior of the backrest. Optionally, a manually releasable plug is provided as a plug connection.

In a particularly preferred manner, this electrical line is laid in the interior of one of the two vertical struts, wherein the electrical contact is closed by the vertical strut engages in its unique nominal position.

Although the present invention has been described above with reference to a preferred embodiment, it is not limited thereto, but can be modified in a variety of ways.

Finally, the features of the subclaims can be combined substantially freely with one another and not by the order given in the claims, provided that they are independent of each other.

Claims (8)

1. Head restraint (10) for installing in individual seats or rear bench seats of motor vehicles, which head restraint is movable from a normal position into an accident position by means of a mechanism which is activatable in a sensor-controlled manner, wherein

   a) a housing body (14) of the head restraint is fixedly connectable to the seat,
   characterized in that

   b) an upper impact plate (16) and a lower impact plate (18) are connected to the housing body (14) by the mechanism,

   c) wherein the upper impact plate (16) is mounted so as to be pivotable from a substantially horizontal orientation into an upright, substantially vertical orientation,

   d) wherein the mechanism is designed to move the lower impact plate (18) forwards in the direction of travel in order to take up the accident position,

   e) and at the same time to pivot the upper impact plate (16) upwards about a connecting spindle (20) between the upper and lower impact plates.
2. Head restraint according to Claim 1, wherein the mechanism contains mechanically effective spring elements which are prestressed in the normal position.
3. Head restraint according to Claim 1 or 2, wherein the mechanism contains at least one articulated arm (24), the limb of which connects the upper impact plate (16) to the housing body (14).
4. Head restraint according to one of the preceding claims, wherein, in the normal position, a magnetic switch with a locking bolt locks the upper impact plate (16) to the housing body (14), and the magnetic switch is connectable to a signal line of an airbag activation system present in the motor vehicle.
5. Head restraint according to Claim 4, wherein the signal line is guided through an anchoring strut (12) of the head restraint.
6. Head restrain according to one of the preceding claims, wherein the upper impact plate (16) contains at least two mutually telescopic parts.
7. Rear bench seat for motor vehicles with a head restraint (10) according to one of the preceding claims.
8. Individual seat for motor vehicles with a head restraint (10) according to one of the preceding Claims 1 to 6.

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